Tube and method of making the same



June 10, 1952 R. H. VON LIEDTKE TUBE AND METHOD OF MAKING THE SAME 3 Sheets-Sheet 1 Filed Sept. 4, 1945 INVENTOR. fflw/Mflmmmrm Q2; r? k 147 ORIVt'Y.

June 10,1952 R. H. VON LIEDTKE 2,599,878

TUBE AND METHOD OF MAKING THE SAME Filed Sept. 4, 1945 5 Sheets-Sheet 2 I N VEN TOR.

ATTORNEY.

June 10, 1952 R. H. VON LIEDTKE TUBE AND METHOD OF MAKING THE SAME 3 Sheets-Sheet 3 Filed Sept. 4, 1945 k m; 5 Z M WM m NV 7 man w Y B 2% @A Patented June 10, 1952 TUBE AND'METHOD ems-masses SAME Rudolph 11:" m; hiedtkef- Ghicag'o; rl -z assig nor, -I -=by "mesne assignments} to" McG'raw *Electric Company; -'a *corporation of 1. Delaware ;Appli cation- Septen1ber 4',1945,'. Seria'lN6. 614,355

1 -This'invientioni relates to'anf article such as a .Itube. formed'of layers of -pa'per'pulp orother fibrous'materials which in the case'of thetube is formed of wound layers of pulp and also relates to'the'method of' securing successive layers together in a manner toflpfr'oduce the" effect of stitching successive layerstogether.

For the sake of simplicity indescribingthe in- I vention, the description willbe"directed tolthe method of producing. atwoundpap'er'tube, though it is 'to be-understoodtthat theinv'ention isnot I limited'solely totubes and theirrmanufactu're, but f is applicable to.other. shapes "of articles-where they aremanu facturedLf-rom a plurality of layers of paper or similaripulp.

In manufacturing I tubes formed ofiwo'und paper pulp or other fibro'us'rnaterialslit. has been foundthat sometimes thefsuccessiv'e' layers of :the paper'pulp 'do-not adhere to .preceding'layers as l :firmly as n'iight' be .wdes'ired and; in" addition to 7 this, it frequently happens that during the winding air or water is trapped between the" oncoming I layer and the partially-wound tube thus produc- 'ing voids in'the wau'or theftubefifThese voids and I this lack of adherence inateiijallyiweakens the tube even after the'tube'is impregnatedwith a nonabsorbent, binding material. Infaddition to this, the'dielectric stlfengthof' the tube is lowered.

' This invention is designed to" overcome'the i" above" noted defectsand objects of I this invention areto provide 'a'tube and a method of'maki ing the'same in which thesuccessive "layers of 'the paper pulp are securely attached tdpreced- I 'ingl'ayers' in such amanner as to' produce the effect of stitching successive layers :together, the

T process also immediately aifording' relief of the air or water trapped in the voids at the'time the "voids tend to form during'the'winding of the chine.

Figure 3 is a' fragmentary view showing'the manner in which the stitching roller or drum operates.-

'Figure-llis a view showing a -"furtherfferm of i stitching drum.

Figure "5' is av1ewofa fragment of a tfube vvith a temporary. sea-ling coating on the outer 'surfaceofitheftube. I H I I 'Figure 6 is a fragmentary viewofa portion of the impregnated'tube. V V I I .Figure '7 is a fragmentaryview of a--portion of a tube showingavoidin the-tube. II I Figure. 8 is a diagrammatic-viewshowing the paper pulpfbeing' wound ona'mandrel.

'iFigure 9 is aiperspective' view 'orFthe .tu'bas it comes from the "tube forming; machine.

.' QFigure' lIis'a I I j Figure 12 isa' fragmentary view ofa portion of Figure 10 is'a'view oftafragmentof the tube,

'suchview being in section-and *partly 'broken away. v v v view of "thejmpregnating-itank.

' the tube, suchviewbeing partly in section show- T Figure 13is a view corresponding totFigure 12 mg one stage in process of impregnation.

' 1 showingfa further step in'the process of'inipregnation.

'Figure 14 is a viewcorrespondingto'l igure 12 showingitherfinished impregnatedtube. I II In eari mgeut the process a convention ltype off tube for'ming machinefrnay. be employed in T which: a tan I is provided. for the papeiflj'pulp 2.

i This paberipmp .is' fed to the tank any."suit- 5} ableffmanner; not shown, and ismammmeu at the properleveL' A hollow jdrum or"rollerv3 is provided and h'as a perforated. perip era portion surroundedby ascreenA. A' partialvacuum v istpiroducdwithin the drum '3' and the paper pulp is sucked up" against thedrum, the dr'um'being rotated in thedirectionrindicated pulp passes: to an intermediate hollowsperforated drum 5 which is surrounded with? "layer a of; felt orrsuitable material 6 and preferably a ihigherivacuum is produced in -the druni fii {:Jlhe r m 5 ece e ela n Pap ln r m the tube is wound. fIhe-machineis pro vided with a plurality of mandrels 1' carried inf s uitable're- .volubly mountedheads fi which are slotted as indica-ted at 9 to receive thereducedtrunnions l0 of-themandrels. The heads --8 and the mandrels "1' are adapted to. be regularly indexedto bring successive mandrels into operative-position and locking, means are provided for temporarily lock- Y ingthe heads and the mandrels intheir successivefpositions. I I v The locking jmeans may "take any; Suitable form; For instance, it may consist ofalever ll pivotally mounted asindi'cate'd at" l2? and pro- The heads 8 and It frequency happens that voids or spaces are formed as indicated at 25 during the winding of the tube. These spaces or voids are produced by entrapped air or water between the oncoming sheet of paper pulp 26, see Figure 8, and the partially formed tube at the point indicated by the reference character 21. 7

It is to be noted also that wherever any of the stitching points reaches one of the voids that the locking means [3 constitute indexing means 7 and thus allow the mandrel carrying heads to be indexed as the tubes are completed. rails l5 extend part-way around the heads and prevent escape of the trunnions from the slots,

9 except in one position, for instance, the lefthandrposition of Figure 1, to allow the removal of a wound tube from a mandrel. The machine may be driven in any suitable manner. For instance, in accordance with the usual practice the drum may be driven by means, notfshown,

and may thus drive the lower drum 3 and the mandrel 1 on which the tube is being wound. The machine thus described is the conventional type of tube forming machine and the usual accessories'are, of course, provided in accordance with the usual practice. r

This invention contemplates the stitching or securing of successive layers to preceding layers during the formation of the wound paper pulp tube. The stitching is accomplished by means of a stitching roller I6 which is journaledfat opposite ends in the bell crank levers 'II pivotally mounted as indicated at [8 upon floating pivoted heads 19 loosely carried by the central shaft 20, which central shaft 20 is rigid withthe end heads 8. The upper portions of the bell crank levers H are joined by means of a transverse bar 2|. This transverse bar constitutes means whereby pressure may be applied. between the stitching roller l6 and the tube. The operator, in the instance chosen for illustration, .presses against the transverse bar 2| and thus forces the stitching drum or roller [6 against the tube while it is being wound. Any other suitable means may be provided for accomplishing the same result, the means chosen being merely one of many possible ways of accomplishing the de- Guard the air or water entrapped in the void is allowed to escape and the formation of voids is very much reduced if not substantially prevented.

It is to be noted that the stitching roller is a ;-relatively -lo ng roller and is provided with a multitude of spaced points or pins as shown in Figure 2.

The pressure exerted between the stitching roller I6 and the tube while it is being wound is distributed over a multitude of points and consequently there is no danger of one point digging into the partially formed tube to an inordinate extent. The amountof penetration is gauged or controlled by theamount of pressure employed.

After a tube has been completely wound pressure on thestitching roller I6 is relieved and the heads 8 and the mandrels 1 are indexed one quarter of a turn in the'form shown in Figure 1 to bring a new mandrel into position and to allow the removal of the finished tube. The heads are indexed in the direction shown in Figure l and, it will be seen that the stitching roller l6 is pushed upwardly during this operation and allows free passage ofthe completed tube. It drops back into position toengage the tube being formed on the succeeding mandrel and again pressure is applied through the medium of the pressure bar 2| or in any other suitable manner. The tube, after removal from the mandrel, is

. thoroughly, dried and is later'impregnated with sired result. The stitching roller is provided with a multitude of prongs or pin-like projecting portions 22 which are shown more clearly in Figure 3. It will be seen that as the partially wound tube rotates that the prongs or projections 22 will be forced into the successivelayers and will force the succeeding layers into'preceding layers thus in effect stitching successive puncture one or more layers.

The stitching roller may take otherforYfis.

' For example, as shown in Figure; the stitching roller I6 may have angular or bent points 22 if desired. It willbe seen that by the method pitch in the usual 1 manner... It is preferable,

however, to follow the method ofimpregnating the tube set forth inthe copending application for Impregnated Article and Methodof Impregnation. Serial No. 614,354,.filedSeptember 4, 1945, by Rudolph H. Von Liedtke,'now' Patent 2,478,439. c, '1 V H 7 V In following the method setgforth in:the copending application hereinabove noted, spray means such, as indicatedby the reference character 28in Figure 1 is provided-for spraying a temporary sealingcoating of size 29, see Figure 12, on the outer side of the tube. This spraying takes place during the winding of the last few convolutions of the tube .and any suitablesizing material may be employed, provided it has. the characteristics of sealing the surface of the tube and'also'of disintegrating or disappearing or be- 7 coming ineffective fora .certain temperature hereinabove described the successive layers are firmly united with preceding layers by forcing a portion of one or more layers into or through portions of preceding layers. Thisis illustrated more clearly in Figure 5 in which the completely we nd tube-is indicated by the referenceichart'e' 23-.and -the stitching'points by thefr'efer racter 24. w

range of the pitch thus allowing the coating to either disintegrateor disappear -.at acertain stage in the process of impregnating the tube. A suitable size issilicate of soda which. is, sprayed on the tube as described. It may be sprayed either onthe first few convolutions to thus seal the inner surface of the tubeor may-besprayed on the outer convolutions of the tube ,to seal the outer surface of thetube" The tube withthe sealing coating thereon is thoroughly dried and after drying is placed in the impregnating tank 30, see Figure 11. This impregnatingtank is supplied with heated pitch through the, supply pipe 3| at its lower portion, and th pitch is pumped. from. the upper portion ,of the tank through the outlet pipe 32 by means of a pump 33 or in any other suitable manner so that heated pitch is circulated through the tank. The tank is provided with a lower steam jacket 39. The upper portion of the tank is connected to a threeway valve 35 which is adapted to connect the tank with a suitable source of vacuum by means of the vacuum pipe 36 or with the outside air or air under pressure by means of the air pipe 37 depending upon the setting of the valve.

When the tubes are positioned within the tank the pitch is caused to circulate and the three-way valve 35 is turned so as to produce a vacuum in the upper portion of the tank. This lowers the temperature of the pitch and prevents destruction of the sealing coating. The air it will be noted which is entrapped within the wall of the tube flows radially inwardly in one direction only away from the sealing coating. After a suitable interval of time the three-way valve i turned to admit air to the upper portion of the tank and to relieve the vacuum. The pitch now fiows radially from the uncoated inner side of the tube towards the coated side of the tube and thus uniformly impregnates the wall of the tube. When the vacuum is relieved the temperature of the pitch rises and the sizing coating or sealing coating 29 disappears or is substantially destroyed after a predetermined interval of time and allows the pitch free access to the outer surface of the tube. In this way there is no chance of air being trapped within the wall of the tube which would prevent even and complete penetration of the pitch. The sealing coating is indicated in Figures 5 and 12 and a fragment of the finished tube is indicated in Figures 6 and 14. For the sake of simplicity, it is to be noted that the stitching points have been omitted in Figures 7, 10, 12, 13, and 14.

The stitching of the tube binds successive layers together and relieves the voids. The result of this is that the successive layers of the tube are very firmly bound together not only by the binding action of the pitch which is a waterproof, binding, impregnating agent, but also due to the stitching of the successive layers.

The stitching occurs at a multitude of closely spaced points, a few only of which have been shown in Figures 5 and 6.

It will be seen that a novel method of binding successive layers of a paper pulp tube together has been provided by this invention by means of r a stitching process which actually forces portions of succeeding layers into portions of preceding layers at a multitude of closely spaced points and which thus causes a very firm interlocking or unification of the layers of paper pulp composing the tube. It will be seen further that the method does not slow up the normal operation of winding or forming these paper pulp tubes but may be followed with the utmost ease and may be adapted to ordinary types of tube forming machines with only minor alterations.

The expression paper pulp appearingin the specification and claims is not intended as a limiting expression as it is obvious that this invention is applicable to any type of article and to the process of making such article where the article is made from fibrous pulp or fibrous material whether it is strictly paper pulp or not.

Although this invention has been described in considerable detail, it is to be understood that such description is intended as illustrative rather than limiting, as the invention may be variously embodied and is to be interpreted as claimed.

I claim:

An article of manufacture comprising a tube formed of a plurality of layers of paper pulp pressed into ,firm contact with each other throughout their extent wound one upon another, said tube having succeeding layers pressed into the body of preceding layers at a multitude of spaced points to stitch the layers together, the points at which successive layer are stitched to the body of preceding layers being spaced both circumferentially and radially from each other, said tube being characterized by the fact that it is a compacted structure throughout its extent.

RUDOLPH H. VON LIEDTKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 549,999 Fairbanks et al Nov. 19, 1895 1,037,671 Seigle Sept. 3, 1912 1,465,177 Richter Aug. 14, 1923 1,550,648 Perry Aug. 18, 1925 1,854,230 Schur Apr. 19, 1932 1,864,674 Schur June 28, 1932 1,957,732 Rowe May 8, 1934 2,043,351 Fourness et a1 June 9, 1936 2,106,246 Fourness Jan. 25, 1938 2,335,722 Adams Nov. 30, 1943 2,374,086 Ferla Apr. 17, 1945 

